In re Kao, 2011 WL 1832537 * 10 (Fed. Cir. 2011) (“This is not a case where the Board relied on an unknown property of prior art for a teaching. Rather, Maloney’s express teachings render the claimed controlled release oxymorphone formulation obvious, and the claimed ‘food effect’ adds nothing of patentable consequence.”). Further on this point, we think that the following guidance from In re Dillon, 919 F.2d 688, 692-93 (Fed. Cir. 1990) (en banc), is instructive:

This court, in reconsidering this case in banc, reaffirms that structural similarity between claimed and prior art subject matter, proved by combining references or otherwise, where the prior art gives reason or motivation to make the claimed compositions, creates a prima facie case of obviousness, and that the burden (and opportunity) then falls on an applicant to rebut that prima facie case. Such rebuttal or argument can consist of a comparison of test data showing that the claimed compositions possess unexpectedly improved properties or properties that the prior art does not have . . . . There is no question that all evidence of the properties of the claimed compositions and the prior art must be considered in determining the ultimate question of patentability, but it is also clear that the discovery that a claimed composition possesses a property not disclosed for the prior art subject matter, does not by itself defeat a prima facie case.